I just had all four wisdom teeth removed. The doctor suggested not smoking for 10 days. Why is that suggested?
As we all know, smoking, in general, is bad for you. After the extraction of four wisdom teeth, there are sutures placed, bone often grafted in the sockets, large areas of swelling, and bleeding and blood clotting associated with the procedure.

There are a number of scientific reasons as to why smoking after a mouth operation is bad for you:

Cigarettes have 4,700 chemical compounds, including 60 known carcinogens. Post-op smoking is especially bad because these chemicals may cause periodontal disease, which causes bone loss and requires more surgery.
Smoking increases the risk of tooth loss after surgery.
Smoking causes a decrease in the body's inflammatory response, which affects the healing of wounds and the regeneration of bone and gingiva, the blood vessels surrounding your teeth.
Cigarettes decrease gingival blood flow. This also slows down the inflammation process, which heals the area and prevents infection.
After an operation as extensive as having all four wisdom teeth removed at once, it is critical to stay away from the heat, nicotine, and associated problems that cigarette smoking can cause.